Numerical and experimental investigation of the spray quenching process with an Euler-Eulerian multi-fluid model

Abstract

An Eulerian spray model for simulations of spray quenching and cooling in water mist chambers has been developed. Spray quenching allows targeted cooling of heated mechanical components to obtain increased material strength properties by modifying the micro-structure evolution. For the numerical multi-domain simulation it was necessary to implement a heat transfer model for the fluid–solid interface taking into account the increased heat transfer due to phase change of impinging droplets. The droplet size distribution of the spray is represented by discrete size classes for which separate transport equations are solved. The main challenge of the simulation was the long process time of several minutes. To reduce simulation time, a new time step sub-cycling method for the evaporation model and a method for periodically frozen fluid flow have been developed. The aim of this paper is to present an enhanced Euler-Eulerian spray model capable for the simulation of the spray quenching process. For model validation, measurements of the temperature history at certain locations within a quenched test geometry have been performed and compared with the numerically predicted results from the CFD simulations. The paper discusses the numerical method, the experimental set-up, and demonstrates the feasibility of the workflow for industrial applications.